Yu. S. Dadoenkova, F. F. L. Bentivegna, N. N. Dadoenkova, R. V. Petrov, I. L. Lyubchanskii, and M. I. Bichurin

J. Appl. Phys. 119, 203101 (2016)

We present a theoretical investigation of the Goos-Höanchen effect upon light reflection from a heterostructure consisting of an electro-optic film deposited on a magneto-electric film grown on a nonmagnetic dielectric substrate. It is shown that the linear magneto-electric interaction leads to an increase of the lateral shift even in the absence of any applied electric field. The presence of the electro-optic layer enables the control of the Goos-H€anchen shift and of the position of its maximum (with respect to the angle of incidence) through a variation of the magnitude and orientation of an applied electric field. It is also demonstrated that applying an external magnetic field in order to reverse the magnetization in the magnetic layer results (under the influence of the magnetoelectric interaction in the system) in a sign reversal of the lateral shift but a nonreciprocal change of its amplitude.

Fig1. Evolution of the reduced lateral shift ΔXps with the incidence angle Θ and the orientation angle φ of the external electric field in the (a) YIG/GGG structure and (b) in ZnSe/YIG/GGG structure upon a reversal of the magnetization.

M. Mruczkiewicz, P. Gruszecki, M. Zelent, and M. Krawczyk

Phys. Rev. B 93, 174429 (2016)

We investigate theoretically themagnetization dynamics in a skyrmionmagnonic crystal. Collective excitations are studied in a chain of touching ferromagnetic nanodots in a skyrmion magnetic configuration. The determined dispersion relation of coupled skyrmions shows a periodic dependence on the wave vector, a characteristic feature of the band structure in magnonic crystals. By spatial analysis of the magnetization amplitude in the magnonic bands we identify the excited modes as breathing and clockwise gyrotropic dynamic skyrmions. Propagating with a negative and positive group velocity, respectively, these high- and low-frequency excitations can be further explored theoretically and experimentally for fundamental properties and technological applications in spintronics and magnonics.

Fig.1. Structures considered in this study, with an out-of-plane bias magnetic field Bz directed along the z axis.

A. L. Solovjov, L. V. Omelchenko, V. B. Stepanov, R. V. Vovk, H.-U. Habermeier, H. Lochmajer, P. Przysłupski, and K. Rogacki

Phys. Rev. B 94, 224505 (2016)94, 224505 (2016)

The pseudogap (PG) derived from the analysis of the excess conductivity σ'(T ) in superlattices and double-layer films of YBa₂Cu₃O_7−δ-PrBa₂Cu3O_7−δ (YBCO-PrBCO), prepared by pulsed laser deposition, is studied for the first time. The σ'(T) analysis has been performed within the local-pair (LP) model based on the assumption of the paired fermion (LPs) formation in the cuprate high-Tc superconductors (cuprates) below the representative temperature T^∗ >>Tc resulting in the PG opening. Within the model, the temperature dependencies of the PG, Δ^∗(T), for the samples with different number of the PrBCO layers (NPr) were analyzed in the whole temperature range from T^∗ down to Tc. Near Tc, σ(T ) was found to be perfectly described by the Aslamazov–Larkin (AL) and Hikami–Larkin (HL) [Maki–Thompson (MT) term] fluctuation theories, suggesting the presence of superconducting fluctuations in a relatively large (up to 15 K) temperature range above Tc. All sample parameters were found to change with increase of NPr, finally resulting in the appearance of the pronounced maximum of Δ^∗(T) at high temperatures. The result is most likely due to increasing influence of the intrinsic magnetism of PrBCO (μPr ≈ 4μB) and suggests the possibility to search in that way the change of interplay between the superconductivity and magnetism in cuprates. 

Fig.1. Δ^∗(T)/Δmax as a function of T/T^∗ for studied YBCOPrBCO superlattice SL3 and sandwich SD2 compared with reference Fe-pnictide samples SmFeAsO_0.85 (Tc ≈ 55 K)  and EuFeAsO_0.85F₁₅ (Tc ≈ 11 K).

Y. V. Kudryavtsev, A. E. Perekos, N. V. Uvarov, M. R. Kolchiba, K. Synoradzki and J. Dubowik

J. Appl. Phys. 119, 205103 (2016)

Magnetic and transport properties of near stoichiometric metastable FexMnyGaz alloys (46x52,17y25, 26z30) with face-centered cubic (FCC), body-centered cubic (BCC), and twophase (FCCþBCC) structures are investigated. The experimental results are analyzed in terms of first-principles calculations of stoichiometric Fe2MnGa alloy with the L21, L12, and the tetragonally distorted L21 structural orderings. It is shown that the pure BCC and FCC phases have distinct magnetic and transport properties. Two-phase Fe2MnGa alloys have magnetic and transport properties typical of the mixed BCC and FCC phases. Among the investigated alloys, Fe46Mn24Ga30 has a martensitic transformation accompanied with significant changes of its magnetic and transport properties.

Fig.1. Temperature dependencies of normalized magnetization of bulk Fe2MnGa alloys taken at H=50 kOe. Numbers near the M(T)=M_max curves indicate alloy sample. The M(T)=M_max plots for all the samples (except sample 5) practically coincide for the cooling and warming scans, therefore only the warming scans are presented.